The present invention relates generally to rectifying and smoothing circuits and more particularly to a rectifying and smoothing circuit capable of rectifying and smoothing with good response characteristic and, moreover, with little ripple.
In a known rectifying and smoothing circuit, its output contains a large ripple component. This ripple content increases with decreasing frequency and with increasing input level. In the case where a rectifying and smoothing circuit of such large ripple component is used as a circuit for obtaining a control voltage for a voltage-controlled, variable-gain amplifier circuit, the gain of the variable-gain, amplifier circuit is controlled by the ripple, and the output signal thereof acquires a great distortion.
Accordingly, in order to reduce this ripple component, it is necessary to cause the rectifying and smoothing circuit to possess an amply large time constant with respect to the low frequency band of a signal to be rectified. However, when the time constant is made amply large in this manner, the response characteristic of the rectifying and smoothing with respect to an input signal becomes poor.
In the known rectifying and smoothing circuits, therefore, it has been almost impossible to accomplish rectifying and smoothing with small ripple component in the output signal and, moreover, with good response characteristic.